I think he surpasses Becker, Edberg, and Wilander firmly at this point. None of those guys were ever so consistent for 6 years plus as Djokovic has been, were solidly the best player in the World for over 2, had a year like Djokovics 2011 (Wilander in 1988 had 3 slams, but not the dominance of the regular tour of Djokovic, and barely even got to number 1 over slamless Lendl), were as good across all types of surfaces. Only in slam count are they comparable at this point.

I see him on par with people like Newcombe, Hoad, and Perry right now, but a bit behind Agassi and McEnroe. He will be on par with Agassi and McEnroe when he wins his 7th slams, and on par with Lendl, Connors, when he wins his 8th. Actually if he wins the French to make it a career slam (which he probably will this year) he moves up even faster than that.